1. Field of the Invention
The present invention relates to an improved support assembly for a circuit-interrupting device, and more particularly to an improved support assembly for a massive circuit-interrupting device normally intended for dead circuit manipulation.
2. Description of the Prior Art
Support assemblies for circuit-interrupting devices, such as high-voltage fuses, are well known. Such support assemblies have taken many forms and have been adapted for use with a wide variety of circuit-interrupting devices. Although the devices may be mounted in just about any position, prior art support assemblies generally include an upper and a lower mounting which are selectively engageable with respective upper and lower end fittings on the circuit-interrupting device. Often the lower end fitting and mounting cooperate to permit not only engagement between the two, but also rotation of the lower end fitting in the lower mounting. This rotation permits rotation of the device about the lower mounting. Also generally speaking, the upper end fitting and upper mounting are selectively engageable. The rotation of the device about the lower mounting permits selective engagement and disengagement of the upper end fitting and mounting. When both end fittings engage both mountings, the device is referred to as being in the closed position wherein a circuit is completed therethrough. When the lower end fitting has been rotated in the lower mounting to permit disengagement of the upper end fitting and mounting, the fuse is in the so-called opened position and the circuit therethrough is open. Such prior art support assemblies are very common in enclosures which house a variety of electrical gear. They permit easy manipulation of the devices, including easy insertion or mounting and removal or demounting of the devices from the enclosures.
Some circuit-interrupting devices are rather massive, that is, are quite heavy and large. Because of their size and weight, such devices, often current-limiting fuses, have usually not been supported by support assemblies as described above. This is because their size renders difficult the rotation of the device within the cramped quarters of an enclosure, and because their weight is felt to place too great a strain on prior art end fittings and mountings during opening and closing operations.
Typically, such massive circuit-interrupting devices have been designed and built to accommodate so-called dead circuit manipulation. Specifically, the circuit in which such devices are contained is first de-energized prior to manipulation thereof. Then, the device is manually grasped by an operator who removes the device from, or places the device in, its support assembly. These support assemblies generally comprise spring-clips or similar apparatus.
Circuit-interrupting devices usable with the rotational mountings and end fittings, as described above, may be adapted for rotation to disengage their first end fitting and mounting in such a manner as to effect circuit or load interruption. In this event, the upper mounting is replaced by or contains a circuit interrupter, for example the type of circuit interrupter disclosed in co-pending, commonly-assigned United States patent application, Ser. No. 660,872 filed on Feb. 24, 1976. Because massive circuit interrupting devices have not been adaptable to such rotational mountings, it has not been possible to mount such circuit-interrupting devices in such a way that movement thereof could effect circuit interruption. Accordingly, not only are such massive devices generally used only in a dead circuit manner, but also such devices have hitherto been unable to perform a load breaking function upon manipulation thereof.